Blockage of human arteries is a widespread malady and, as such, represents a significant health concern. Blockages reducing blood flow through the coronary arteries to the heart can cause heart attacks, while blockages reducing blood flow through the arteries to the brain can cause strokes. Similarly, arterial blockages reducing blood flow through arteries to other parts of the body can produce grave consequences in an affected organ or limb.
The build-up of atherosclerotic plaque is a chief cause of blockages, termed stenoses, which reduce blood flow through the arteries. Consequently, several methods have been introduced to alleviate the effects of plaque build-up restricting the artery. One such method is a procedure termed angioplasty, which uses an inflatable device positioned at the stenosis to dilate the artery. A typical angioplasty device is disclosed in U.S. Pat. No. 4,896,669 to Bhate et al. The angioplasty device of Bhate et al includes an inflatable balloon which is attached to the distal end of a hollow catheter tube. The proximal end of the catheter tube is attached to a fluid source.
To treat an arterial stenosis, the balloon of Bhate et al is introduced into the artery in a deflated state and guided through the artery over a guide wire to a position adjacent the stenosis. Fluid from the fluid source is then infused into the balloon via the catheter tube to inflate the balloon. As the balloon expands, it presses against the arterial wall in the region of the stenosis, dilating the artery at the stenosis and restoring it to a sufficient size for adequate blood flow therethrough. The balloon is then deflated and removed from the artery, thereby completing the treatment.
A desirable feature of a balloon catheter is that the balloon be able to assume a neatly folded and compact configuration when it is in the deflated state. This is so in order to facilitate the insertion and passage of the balloon catheter through the blood vessel. Passage of the balloon through the vessel becomes even more difficult to accomplish if the structure of the balloon catheter is relatively complicated. Specifically, it has been proposed that a cutting element be used in concert with the operation of the balloon to facilitate dilation of the vessel at the stenosis As can be easily appreciated, safety also becomes an issue of concern when cutting elements are included. Even more so when these cutting elements are mounted directly onto the outer surface of the balloon.
In light of the above, it is an object of the present invention to provide a method for manufacturing a folding balloon catheter having a balloon with a predictable folded configuration when the balloon is deflated. It is another object of the present invention to provide a method for manufacturing a folding balloon catheter having atherotomes mounted on the outer surface of the balloon. It is yet another object of the present invention to provide a method for manufacturing a folding balloon catheter having atherotomes mounted on the balloon which is relatively easy to perform and comparatively cost effective.